Telephone-receiver.



N..BALDWIN.

TELEPHONE RECEIVER.

APPLICATION FILED 111111.21. 1913.

Witnesses 1 :B 22m A/ M dlladj l H one.

NATHANIEL BALDWIN, or MILL CREEK, UTAH.

TELEPHONE-RECEIVER.

Specification of Letters Patent. Patented Sept. 14, 1915.

Application filed March 27, 1913. Serial Nb. 757,220.

State of Utah, have invented new and useful Improvements in Telephone-Receivers, of which the. following is a full, clear, and exact description.

The present invention appertains to telephone receivers, and is particularly an im-' provement over my former Patent No.

957,403, issued MaylO, 1910.

It is the object of the present invention -to provide a very compact and efiective arrangement of the working parts.

The invention is illustrated in the accompanying drawing, wherein: Figure 1 is ametrical section through a watch case form of receiver. Fig. 2 is a similar section of another form of receiver, portions being shown in elevation. Fig. 3 is a cross section taken on line AB of Fig. 1. Fi 4 is a sectional detail taken on the line D of Fig. 3.

Each form of the invention embodies a shell or casing l of circular outline, which has the rim of a cup 2 seated against its edge.

Disposed within the shell 1, is a circular.

permanent magnet 5 divided at one side to provide spaced poles located at the opposite sides of the medium plane of the magnet 5. U-shaped pole pieces 3 and 4 each has one of its limbs resting directly against and secured to one pole of said magnet, by means of screw or securing element 6. The limbs of the pole pieces 3 and 4 project toward one another beyond the poles of the permanent magnet, and an electromagnet is secured between the pole pieces. This electromagnet embodies a flattened tube 7 having its sides approximately flush with the ends of the pole pieces 3 and 4, and provided with flanges or heads 8 at its ends resting against the limbs of the pole pieces. The electromagnet embodies a coil wound around the tube or spool 7, as will be apparent, and as is well understood. An armature 9 isful- .crumed within the tube or electromagnet 7 by means'of the-wires onpin's 10 carried by the tube 7. r

Blocks 11 are secured between the pole pieces 3 and 4 to properly space them, and to assist in holding the tube or spool 7 in position.

A diaphragm '12 is clamped against the rim otthe cup2, by means of a cap or ear piece- 13 threaded upon the rim of the shell 1, said diaphragm being parallel with the me lc llilan plane of the permanent magnet 5. Within the permanent magnet, and the armature 9 is disposed radially of the permanent magnet, a link 14 connecting the inner end of the armature 9 and the central portion of the diaphragm. The diaphragm 12, is provided with a Washer 15 at its center through which the link 14 is engaged, to prevent the breakage of the diaphragm or the loosening of the link 14 therefrom.

A doubled spring 16 has one end engaged to the outer end of the armature 9, and has its other end engaged to the projecting end of that limb of the pole piece 4 which is secured to the respective pole of the permanent magnet, so that the spring 16 proepole pieces 3 and 4 project inwardly.

jects between the poles of the permanent positioning of the pole pieces and spring relative to the permanent magnet as illustrated and; described.

A binding post 17 is carried by the cup 2 remote from the poles of the permanent magnet, and is clamped thereto by means of a nut 18 threaded upon the binding post. Insulating washers 19 are carried by the post 17, and an insulating sleeve 20 is mounted upon the post between the washers 19. Terminal elements 21 are engaged to the sleeve 20 and are connected to the terminals of the coil of the .electromagnet. The terminals 22 of the conductors are engaged to the sleeve 20 to be in electrical connection with the respective terminal elements 21. A nut 23 is threaded upon the post 17 for clamping the other elements 6 necting the inner end of the armature'and the diaphragm, and a doubled spring having its ends engaged to the other end of the armature and the projecting end of that limb of one pole piece which'rests against 10 and is secured to the respective pole of the permanent magnet, the spring projecting between the poles of the permanent magnet,

whereby the positioning of the pole pieces and spring relative to the permanent magnet provide a compact arrangement.

NATHANIEL BALDWIN.

Witnesses:

N. J. HANSEN, GEO. A. DIXON. 

